The quick start guide says 3 hours to charge, where as here HTC Desire - When I first receive my phone, do I need to charge the battery? it states 8 hours. Which should I follow? Also, can I have it switched on while I charge so I can set it up? And I imagine I should let it fully discharge before charging it again, but how many times is this appropriate for? The first 2 or 3 or more times? Thanks.